1. Field of the Invention
The present invention relates generally to composite components and, more specifically, to a method of magnetically reinforcing composite components as well as articles of manufacture made from them.
2. Description Of the Related Art
The term "solidifyable" material is defined here as a fluid or liquid or pseudo-liquid which solidifies or hardens at a later stage into a substantially solid or rigid form. Generally, these solidifyable materials are poured or injected into a mold or cast or other type of "form" while in a fluid state, and then allowed to solidify into their rigid state, for example, by cooling, chemical reaction, or other. Examples of these solidifyable materials are plastic, glass, ceramic, rubber, concrete, even metal and others. Some of the plastic materials include epoxies, thermo-set materials, thermo-plastic materials and others. These solidifyable materials are commonly used in many forms of manufacturing and for many articles of manufacture. Although these solidifyable materials have wide and varied uses for manufactured components, many plastic materials have limited strength, and for some applications, such as for making gears, bearings, and the like, they have limited ability to resist surface "wear".
It is known that "filler" materials can enhance various properties of these solidifyable materials. These filler materials come in a wide variety of substances, shapes, and sizes, and have in the past included such substances as glass, carbon fibre, and the like. Generally, the filler materials are added to improve the strength of the solidifyable materials without otherwise significantly degrading the characteristics and performance of the solidifyable materials in other ways. An example of a filler material to reinforce a plastic article is disclosed in U.S. Pat. No. 3,061,888 to Bradham. This patent discloses adding filler material to a predetermined location of a mold prior to adding plastic material to the mold. However, this process suffers from the disadvantage that it is difficult to employ in many applications and is undesired. As a result, it is desired to add and mix filler materials with solidifyable materials prior to the injection or pouring of the solidifyable material into a mold.
During molding of solidifyable materials, difficulty has sometimes been experienced when attempting to fill small recesses of a mold with the filler materials, especially when the filler material was in the form of elongated fibers. The recesses generally have a somewhat narrowing or otherwise restricted in-flow path during the molding operation. As a result, the elongated fibers have a tendency to "dam up" in the entrance to the recess, resulting in incomplete filling of the recess, or resulting in a low concentration of the filler material in the recess where their presence would be most desirable. One attempt to overcome this difficulty is to cause migration of the filler material to concentrate it in selected locations of the component to be molded. An example of such a process is disclosed in U.S. Pat. No. 3,870,775 to Castro et al. for a method of making shaped articles. This patent discloses migrating filler material to a predetermined location of a shaped article by centrifuging a flammable mixture of curable resin and fibrous filler. However, this centrifuging process suffers from the disadvantage that it is expensive and is undesired.
Another example of a process to cause migration of the filler material is disclosed in U.S. Pat. No. 3,098,401 to Breeze, Jr. et al. for a method of making a drill plate. This patent discloses attracting steel particles and forcing them to migrate from other parts of a liquid suspension medium to a position about a magnetic core which is utilized to locate a drill hole at a predetermined location in a drill plate. However, this process suffers from the disadvantage that filler particles are left throughout the molded article and is undesired.